The present invention relates to safety apparatus which finds application, for example, in automatic door apparatus and machine tools.
Automatic doors are in widespread use in various applications, such as elevators, buses and trains. Considerations of personal safety require that doors not be closed when there is a danger that a person might be impacted thereby. While not compromising safety considerations, considerations of efficiency dictate that doors be closed as promptly and quickly as possible.
There exist various techniques and apparatus for sensing the absence of a person and his accouterments within a predefined zone and consequently operating an automatic door. U.S. Pat. Nos. 4,029,176; 4,590,410; 4,779,240; 4,976,337; 5,001,557; 5,149,921; 5,276,391; 5,412,297; 5,420,430; RE 33,668 and RE 30,719 exemplify the state of the art. U.S. Pat. No. 5,412,297 employs a tactile obstruction detector, while U.S. Pat. Nos. 4,590,410 and 5,276,391 employ optical detectors. U.S. Pat. No. 2,826,753, which relates to object detection in a confined environment and not to door opening or closing, and U.S. Patents RE 30,719; 4,029,176 and 5,147,410 employ acoustic energy and are believed by applicant to be the closest prior art to the present invention. Other distance and direction measuring apparatus is described in U.S. Pat. Nos. 5,467,072; 5,450,057; 5,373,482; 5,341,344; 5,339,075; 5,337,289 and 5,319,611.
The present invention seeks to provide a secure and efficient door operating system which maximizes door closing efficiency while minimizing the risk of injury to users.
There is thus provided in accordance with a preferred embodiment of the present invention a door control apparatus for vehicles including at least one sensor viewing at least one region in the vicinity of a door, logic circuitry responsive to the at least one sensor for providing at least one region clear output signal, automatic door opening and door closing apparatus responsive at least to the absence of a region clear output signal to cause opening of the door and responsive at least to the presence of a region clear output signal to cause closing of the door.
Furthermore in accordance with a preferred embodiment of the present invention wherein the automatic door opening and door closing apparatus is responsive at least to the absence of a region clear output signal to cause opening of the door and responsive at least to the presence of the same region clear output signal to cause closing of the door.
Additionally in accordance with a preferred embodiment of the present invention wherein the automatic door opening and door closing apparatus is responsive at least to the absence of a first region clear output signal in respect of a first region to cause opening of the door and responsive at least to the presence of a second region clear output signal, different from the first region clear output signal, in respect of a second region different from the first region, to cause closing of the door.
Furthermore in accordance with a preferred embodiment of the present invention, the first and second regions are mutually overlapping, mutually exclusive and partially mutually overlapping.
There is also provided in accordance with a preferred embodiment of the present invention a safety apparatus for preventing injurious engagement of machinery with a user and clothing and accouterments thereof within a predetermined volume including a sensor having two modes of operation, a reference sensing mode of operation for sensing the boundaries of the predetermined volume, and an engagement prevention mode of operation for sensing the presence of a user and clothing and accouterments thereof within the predetermined volume and control apparatus responsive to outputs from the sensor in both of the modes of operation for preventing operation of the machinery when the presence of a user and clothing and accouterments thereof within the predetermined volume could cause injurious engagement.
Additionally in accordance with a preferred embodiment of the present invention, the sensor comprises at least one ultrasonic transducer.
Furthermore in accordance with a preferred embodiment of the present invention, the sensor is operative in the reference sensing mode of operation in the absence of a user or operator within the predetermined volume.
Additionally in accordance with a preferred embodiment of the present invention wherein the sensor is operative in the reference sensing mode of operation with generally the same frequency as it is operative in said engagement prevention mode of operation.
Moreover in accordance with a preferred embodiment of the present invention, the sensor is operative in the reference sensing mode of operation with a frequency much less than it is operative in the engagement prevention mode of operation.
Additionally in accordance with a preferred embodiment of the present invention, the sensor comprises at least two sensors viewing the predetermined volume and together providing an output indication of the location of objects within the predetermined volume in at least two dimensions and wherein the control apparatus is responsive to the output indication for preventing operation of said machinery when the presence of a user and clothing and accouterments thereof at predetermined locations within the predetermined volume could cause injurious engagement.
Still further in accordance with a preferred embodiment of the present invention wherein the control apparatus is operative to be non-responsive to predetermined regions within an outer boundary of the predetermined volume, corresponding to predetermined time domains.
There is also provided in accordance with a preferred embodiment of the present invention a safety apparatus for preventing injurious engagement of machinery with a user and clothing and accouterments thereof within a predetermined volume including at least two sensors viewing the predetermined volume and together providing an output indication of the location of objects within the predetermined volume in at least two dimensions, control apparatus responsive to the output indication for preventing operation of the machinery when the presence of a user and clothing and accouterments thereof at predetermined locations within the predetermined volume could cause injurious engagement.
Additionally in accordance with a preferred embodiment of the present invention, the at least two sensors comprise at least two ultrasonic transducers.
Furthermore in accordance with a preferred embodiment of the present invention, the control apparatus excludes predetermined three-dimensional regions from the predetermined volume corresponding to predetermined combinations of different time domains of the at least two sensors.
There is also provided in accordance with a preferred embodiment of the present invention a door operating system comprising an automatically operable door, a sensor for sensing the presence of an object within a predetermined volume located at the door of the vehicle and above steps leading to the door of the vehicle from the outside thereof, and a door controller operative at least partially in response to an output from the sensor to actuate the automatically operable door.
In accordance with a preferred embodiment of the present invention the sensor is an ultrasonic sensor. Alternatively any other suitable type of sensor may be employed provided that it is insensitive to inputs received from outside the predetermined volume.
In accordance with a preferred embodiment of the present invention, the automatic door operating system is mounted on a vehicle, such as a bus or train and the predetermined volume is located at the steps leading to the door from the outside thereof.
Further in accordance with a preferred embodiment of the present invention, there is provided a vehicle having a chassis, a body and propulsion apparatus, the body including at least one door operating system comprising an automatically operable door, a sensor for sensing the presence of an object within a predetermined volume located at the door of the vehicle and above steps leading to the door of the vehicle from the outside thereof, and a door controller operative at least partially in response to an output from the sensor to actuate the automatically operable door.